The present disclosure relates generally to refrigeration. More particularly, the present disclosure relates to methods for collecting a hydrocarbon refrigerant such as R-600a (i.e., Isobutane) and methods for servicing or repairing a refrigeration system containing such a refrigerant. As used herein, the expression “servicing” or “service” includes repair.
Generally, the refrigeration system of a cooling appliance such as a refrigerator uses a vapor-compression cycle wherein a refrigerant or coolant, such as R-134a, enters a compressor and goes through various processes before traveling through the coils or tubes of an evaporator disposed inside the refrigerator. A fan may be used to circulate air across the coils or tubes of the evaporator so that the refrigerant extracts heat from the air. The cooled air is then used for cooling purposes. In a refrigerator, the cooled air is returned to the freezer compartment and/or the food compartment. The vapor-compression cycle is well known in the art, and therefore will not be discussed in detail here.
During the servicing or repair of the refrigeration system, the refrigerant cannot remain in the refrigeration system because of safety concerns. It should therefore be safely removed from the refrigeration system before servicing or repair. After the servicing or repair, the refrigeration system must be charged with a replacement refrigerant.
Various organizations, such as the Environmental Protection Agency (hereinafter “EPA”) and the World Heath Organization (also known as “WHO”), have attributed negative environmental changes, such as the reduction of ozone layer, to the release of refrigerants into the atmosphere. Recent and continuing environmental objectives and directives thus require the use of more environmentally friendly materials as refrigerants. As a result, refrigerants have been changed from chlorofluorocarbons (CFC) and hydro chlorofluorocarbons (HCFC) to hydro fluorocarbons (HFC), and more recently from HFC to Hydrocarbons (HC). The compositions of these refrigerants are well known in the art, and therefore will not be discussed here.
HC refrigerants require different collecting and servicing processes. Pumps have been used to transfer refrigerant, such as CFC or HFC, from a refrigeration system to a recovery container such as a pouch. However, HC is significantly more flammable than HFC. Therefore, using pumps to transfer HC is not practical due to safety/ignition concerns. In many European countries, the common practice in repair is to vent HC directly into the atmosphere outside of a house. However, the EPA does not permit this type of venting in the United States as it has passed specific regulations for the reclamation and disposal of refrigerants.
It is therefore desirable to have methods for collecting an HC refrigerant and for servicing a refrigeration system containing such a refrigerant that comply with the EPA regulations and to provide a safe and efficient service method.